You will need:
Double knit yarn in green, white, natural and a scrap of black for the eyes and a scrap of red for the mouth
Toy stuffing
2.75mm needles
Small green acrylic pompom

Tension is not important.

Abbreviations

K knit, kfb knit front and back to increase by one stitch, k2tog knit two stitches together to decrease by one stitch, p purl, p2 tog purl two stitches together to decrease by one stitch.